Biomedical subjects

M Okano

Publications and source records attributed to M Okano.

At least 199 records · Page 11Linked to original sources

PubMed1992

[Evaluation of preoperative prism adaptation in patients with acquired esotropia].

A prospective study was carried out of the evaluation preoperative prism adaptation in 77 patients with acquired esotropia. Sixty-three patients who showed a stable esodeviation with prisms of 10 prism diopter or less by alternate prism cover test and fusion response to the prisms were classified as prism responders and were randomly classified into two groups. Thirty-one patients of prism responders underwent surgery based on the prism adapted angle. Patients in the other 32 cases were assigned to undergo surgery for their initially measured angle. On the other hand, 14 patients who did not respond to prism adaptation underwent surgery for their preoperative measured angle of deviation. Success rates with deviations of 0 to 10 prism diopters measured 1 year after surgery by the alternative prism cover test at 5 m and with fusion on Bagolini's striated glasses test were highest (26 [84%] of 31 patients) in prism adaptation responders who underwent surgery for prism determined angle and lowest (3 [21%] of 14 patients) in the prism adaptation nonresponder who showed no fusion response to the prisms.

Adaptation, Ocular↗

PubMed1992

[Motor adaptation in the Bielschowsky head-tilt test in cases of superior oblique palsy].

To elucidate a motor adaptation phenomenon in the Bielschowsky head-tilt test in cases of superior oblique palsy, a gain of the otolith-ocular reflex was studied. The amplitude of ocular counter-rolling (OCR) of the non-paretic eye was measured with a photographic method, using limbal conjunctival marks as landmarks which were marked with indigo carmine. The average preoperative OCR of the non-paretic eye was 10.49 degrees at 30 degrees of head tilt to both sides, but after corrective surgery in the paretic eye the OCR of the non-paretic eye decreased to 8.43 degrees. To clarify the relation between OCR, duration of palsy and vertical deviation of the Bielschowsky head-tilt test (BHP), which was the difference of vertical deviation measured with the head tilted to the left and right shoulders at an angle of 30 degrees, the BHP/OCR ratio was calculated. We found no relation between BHP and OCR, but the BHP/OCR ratio increased proportionally in cases of long-standing palsy, From these results an increased BHP/OCR ratio could be an adaptive phenomenon caused by secondary innervational changes or muscle contracture to minimizing the contralateral head tilt to maintain binocular single vision.

Adaptation, Physiological↗

PubMed1992

[Study on mechanical properties of extraocular muscles. I. Passive length-tension curves in rabbits].

Length-tension curves of detached eye muscles were continuously measured in albino rabbits with a length and tension measuring device developed by the author. The device consists of a strain gauge for measuring passive length-tension, and a position encoder equipped with an eddy current motor. In extending vertical rectus and oblique muscles, an exponential relation was found between length and tension. There was no significant difference between the passive load and extending velocity. The load of the superior rectus muscle was significantly greater than those of the other 3 vertical muscles, and that of the inferior oblique muscle was significantly greater than that of inferior rectus muscle. Each compliance of the inferior rectus muscle or the inferior oblique muscle was significantly greater than that of the superior rectus muscle or the superior oblique muscle.

Animals↗

PubMed1992

Hemagglutination and graft-versus-host disease in the severe combined immunodeficiency mouse lymphoproliferative disease model.

In the course of evaluating the severe combined immunodeficiency mouse-human peripheral blood lymphocyte (SCID-PBL) model of lymphoproliferative disease, we noted hemagglutination occurring in peripheral blood smears of mice with serum human immunoglobulin levels greater than 1.0 mg/ml. The hemagglutinating process was mediated by human anti-mouse red cell antibodies of the IgM class, peaked at five to seven weeks post-transfer of 5 to 7 x 10(7) human PBL and was generally self limiting. However, death resulted in some mice when serum immunoglobulin levels were greater than 3.0 mg/ml. The most severely affected mice had hemagglutination induced congestion of liver, lungs and spleen. Several mice also had lesions consistent with graft-versus-host disease (GVHD) including focal hepatic necrosis and destruction of mouse splenic hematopoietic elements. The lesions associated with hemagglutination and GVHD in SCID-PBL mice are distinct from those associated with EBV-induced lymphoproliferation. Recognition of these pathologic processes are required for a thorough understanding of the SCID-PBL model.

Animals↗

PubMed1991

SCID mouse model of Epstein-Barr virus-induced lymphomagenesis of immunodeficient humans.

Immunodeficient humans are at very high risk of developing Epstein-Barr virus (EBV)-induced lymphomagenesis. Severe combined immunodeficient mice (SCID) have been shown to develop lymphoproliferative disease (LPD) following transfer of peripheral blood leukocytes (PBL) with latent EBV. To study mechanisms of lymphomagenesis, we compared results of engraftment of PBL from normal donors and immunodeficient donors with X-linked lymphoproliferative disease (XLP). Graft-versus-host disease (GVHD) developed in 6 of 10 SCID mice 4 to 8 weeks following transfer of PBL from normal donors. In contrast, none of 9 mice engrafted with PBL from XLP patients with T-cell defects showed GVHD. LPD developed in mice regardless of the immune competence of the donors. The expression of EBV-encoded proteins, results of immunophenotyping, and karyotyping of the LPD lesions revealed lethal oligoclonal LPD owing to transfer of latent EBV in B cells in mice engrafted with PBL from seropositive donors. Polyclonal LDP developed in mice engrafted with PBL from seronegative patients which were infected with B95-8 virus 6 weeks after transfer of the cells. This model is useful for investigating mechanisms of EBV-induced LDP in immunodeficient patients.

Animals↗

PubMed1991

Detection of primary Epstein-Barr virus infection in a patient with X-linked lymphoproliferative disease receiving immunoglobulin prophylaxis.

Serologic diagnosis for Epstein-Barr virus (EBV) infection is problematic when patients receive exogenous immunoglobulin. We recently diagnosed primary EBV infection by detecting EBV-determined nuclear antigen (EBNA) and EBV-DNA in peripheral blood mononuclear cells (PBMC) using immunofluorescence, in situ hybridization and polymerase chain reaction (PCR) techniques in a patient with X-linked lymphoproliferative disease (XLP) who received prophylactic immunoglobulins for EBV infection. These combined techniques may be helpful for early and accurate diagnosis of EBV infection in highly vulnerable patients.

Adult↗

PubMed1991

Immunological comparison between prostate-specific antigen and gamma-seminoprotein.

Prostate-specific antigen (PA) and gamma-seminoprotein (gamma-Sm) were compared by immunocytochemical, immunodiffusion and immunoblotting methods using rabbit anti-PA antibody and rabbit anti-gamma-Sm antibody. Enzyme immunoassays (EIAs) were developed for measurements of PA and gamma-Sm to determine a correlation between serum PA and gamma-Sm levels in patients with prostate cancer. The patterns of localization and distribution of PA and gamma-Sm were identical in prostate tissue sections, including benign and cancerous human prostates. The immunodiffusion study showed that the antigens with which anti-PA antibody and anti-gamma-Sm antibody reacted in seminal plasma and prostate tissue homogenates were identical to each other. In the immunoblotting study, anti-PA antibody and anti-gamma-Sm antibody recognized a single antigen corresponding to a molecular weight of approximately 33,000 both in seminal plasma and prostate tissue homogenates. The EIAs developed in this study were sensitive, specific, and reproducible, and the correlation between serum PA and gamma-Sm values determined by these EIAs was highly significant (r = 0.99, P less than 0.001). These results indicated that PA and gamma-Sm were immunologically identical and that serum PA and gamma-Sm determined by immunoassays using anti-PA antibody and anti-gamma-Sm antibody should be evaluated as identical tumor markers for serodiagnosis of prostate cancer.

Antigens, Neoplasm↗

PubMed1991

Suppression of proliferation of human epidermal keratinocytes by 1,25-dihydroxyvitamin D3. Analysis of its effect on psoriatic lesion and of its mechanism using human keratinocytes in culture.

Psoriasis is a genetically determined chronic disease of the skin, and an accelerated proliferation of epidermal keratinocytes is one of the pathophysiological characteristics of psoriatic lesion. Recently, it was reported that topical administration of 1,25-dihydroxyvitamin D3 was effective for psoriasis. Our study was done to investigate the effect of 1,25-(OH)2-D3 on cell kinetics on human epidermal keratinocytes as a possible mechanism of its effect on psoriasis. After 24-h application of 1 microgram g-1 1,25-(OH)2-D3 ointment to psoriatic lesion, the number of mitotic keratinocytes decreased. When the cultured human keratinocytes were exposed to 10(-8) mol l-1 1,25-(OH)2-D3 for more than 9 days, inhibition of cell proliferation was noted. DNA distribution analysis by flow cytometry showed a decrease in cells in the S phase, and increase in 2c cells. This indicates blockade of the cell cycle in the G1 phase. The cell cycle time was not extended as a result of 1,25-(OH)2-D3-treatment.

Administration, Topical↗

PubMed1991

1 alpha,25-(OH)2D3 use on psoriasis and ichthyosis.

The present work compared the clinical efficacy of topically applied 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25-(OH)2D3) in 16 cases with psoriasis vulgaris, 5 with ichthyosis vulgaris and 8 with X-linked ichthyosis. Sixty-nine percent of the psoriatic cases responded to 1 alpha,25-(OH)2D3 therapy, whereas no ichthyotic patients responded. The present study confirms the previously suggested effectiveness of the active form of vitamin D3 for psoriasis and denies its possible efficiency against the ichthyoses. Direct suppression of hyperproliferative activity of the psoriatic epidermis is considered one of the most plausible mechanisms of 1 alpha,25-(OH)2D3 efficacy, through examination of the aforementioned evidence.

Adolescent↗

PubMed1991

Severe chronic active Epstein-Barr virus infection syndrome.

Reports of unusually severe lymphoproliferative disorders associated with extremely high antibody titers against Epstein-Barr virus (EBV) have recently increased. The syndrome, which we designated severe chronic active EBV infection syndrome, is characterized by persistent or intermittent fever, lymphadenopathy, and hepatosplenomegaly and primarily affects children and young adults. Polyclonal gammopathy and bone marrow suppression are generally observed, and some patients develop B-cell or T-cell lymphoproliferation or lymphoma. Frequently, EBV genomes are detectable in tissues infiltrated with lymphoid cells. Additionally, it is difficult to establish spontaneous or B95-8 EBV-induced cell lines despite the expression of an activated EBV infection. We review and report here the published medical literature and our own experience regarding patients with severe chronic active EBV infection syndrome in an attempt to understand this enigmatic syndrome and the possible pathogenetic mechanism(s) responsible for this disorder.

Chronic Disease↗

PubMed1991

Hematopathologic features of Epstein-Barr virus-induced human B-lymphoproliferation in mice with severe combined immunodeficiency. A model of lymphoproliferative diseases in immunocompromised patients.

The anatomical distribution, morphology, and clonality, of 'non-Hodgkin's lymphomas' in immunocompromised patients are usually distinctly different from NHL occurring in the general population. Mosier DE, Gulizia RJ, Baird SM, Wilson DB: Nature (London) 335:256, 1988 have described lymphoproliferative disease (LPD) of human B cell origin in mice with severe combined immunodeficiency (scid mice) after transfer of human peripheral blood mononuclear cells from Epstein-Barr virus-seropositive individuals. Reported herein is detailed information regarding the morphology, phenotypes, and clonality of LPD lesions in 10 of 18 scid mice that had developed LPD after transfer of peripheral blood mononuclear cells. These lesions were diffuse and monomorphic proliferations of immunoblastoid cells. They were invasive in their growth and often necrotic. Human B cell-related and activation-associated antigens were found on the LPD lesions, although the numbers of cells with the latter antigens were relatively small. Immunofixation electrophoresis for human immunoglobulins in sera of the majority of mice revealed oligoclonal populations, however, phenotypic and cytogenetic analyses showed no definite monoclonality. This scid mouse model is beneficial for understanding the early phases in the pathogenesis of LPD in immunocompromised patients.

Animals↗

PubMed1991

SCID/human mouse model of central nervous system lymphoproliferative disease.

Epstein-Barr virus (EBV) carrying malignant lymphomas of the central nervous system are increasing owing to the increasing numbers of immunodeficient patients. To further understand the pathogenesis of these tumors, we studied the invasiveness of four EBV-immortalized lymphoblastoid cell lines in the brains of immunodeficient mice and the expression of adhesion molecules during this process. We injected four EBV-infected human lymphoblastoid cell lines intracerebrally into nude as well as SCID/SCID CB17 mice. Within 13 to 14 days, lethal brain lymphoproliferative lesions resulted in SCID mice, whereas similar lesions developed in 21 to 24 days in nude mice. Atypical large lymphoid cells aggressively infiltrated brain parenchyma, ventricular, and subarachnoid spaces. No difference in invasiveness was found between the monoclonal lymphoblastoid cell lines grown in long-term culture and polyclonal lymphoblastoid cell lines grown for a shorter duration. Tumors retained the same human immunoglobulin expression and activation antigen profile as the original cell lines. Furthermore, tumors expressed human LFA-1/ICAM-1 and the tumor blood vessels strongly expressed murine ICAM-1, but not MECA 79. Mice injected intracerebrally with peripheral blood leukocytes or normal bone marrow cells from an EBV seronegative individual failed to form tumors confirming the pivotal role for EBV in this process. SCID mice offer advantages for studying central nervous system lymphoproliferative disease.

Animals↗

PubMed1991

Appearance of lectin binding affinity to the zona pellucida during hamster oocyte maturation.

In our previous study, a drastic change in terminal saccharides of glycoconjugates of the hamster zona pellucida associated with oocyte maturation was observed using light microscopic methods of lectin cytochemistry. To understand the mechanism of this change, in the present study, the correlation between the cytochemical appearance of saccharide residues in the zona pellucida and nuclear maturation was examined. Immature hamsters were treated with PMSG and hCG to induce follicular development and ovulation. The animals were euthanized 0 to 26 hrs. after the injection of PMSG or 0,1,2,3,4,5,7,9 or 11 hrs. after the injection of hCG, and ovaries were dissected out, fixed, paraffin embedded and sectioned serially. Every other paraffin section was stained with hematoxylin to observe the status of nuclei and to classify follicular growth and only the fully developed preovulatory follicles were examined in experiments. The peroxidase-labelled lectin-diaminobenzidine procedure was applied to sections. The lectins employed were WGA, SBA, MPA, UEA-I, LotusA and AAA. Germinal vesicle breakdown was observed within 3 hrs. after the administration of hCG. A positive reaction of WGA, SBA or MPA for zonae pellucidae in the fully developed preovulatory follicles appeared 1 hr. after hCG injection, and remained so for the next 10 hrs. UEA-I, Lotus A and AAA reactions were negative for all of the zonae pellucidae observed. The data indicate that the synthesis of saccharide residues such as GlcNAc and GalNAc forming zona components in the follicles is not triggered by germinal vesicle breakdown.

Animals↗

PubMed1991

[Advancement of the anterior portion of the superior oblique tendon in case of traumatic bilateral trochlear palsy].

The effect of the advancement of the anterior portion of the superior oblique tendon on cyclovertical and horizontal deviation was studied in seven cases of traumatic bilateral trochlear palsy by using a synoptometer (Cüppers) and cyclodevinometer (Kolling). The anterior portion of the superior oblique tendon was disinserted and advanced laterally according to the amount of the cyclodeviation in primary position with 1 degree/mm. Surgery was done in 5 cases on both eyes, in 2 cases on one eye. The age of the patients ranged from 20 to 64 years (mean 45 years). The excyclodeviation was significantly reduced (p less than .01), however overcorrection was found in the upward gaze. The mean reduction of excyclodeviation in diagnostic positions of gaze was approximately 10-12 degrees. The vertical deviation was significantly reduced in up and downward gaze (p less than .05), nevertheless overcorrection was found in the upward gaze. The mean reduction of the vertical deviation differed according to their positions of gaze. V-pattern esotropia could not be reduced significantly. Therefore an alternative operative approach must be found which can avoid overcorrection in the upward gaze and moreover correct V-pattern esotropia in the downward gaze.

Adult↗

PubMed1990

Expression of Epstein-Barr virus-encoded proteins and B-cell markers in fatal infectious mononucleosis.

We assessed 33 lymphoid tissues from 15 patients, including 7 with X-linked lymphoproliferative disease (XLP) and 8 patients with sporadic fatal infectious mononucleosis (IM), to determine whether the cellular infiltrate had the immunophenotype and expressed Epstein-Barr virus (EBV)-encoded proteins characteristic of either EBV-immortalized lymphoblastoid cell lines (LCL) or EBV-carrying Burkitt lymphoma (BL) cells. The results of these studies revealed that in 13 cases the proliferating B cells were polyclonal, LCL-like, and in 2 cases they were monoclonal, malignant lymphoma-like.

Adult↗

PubMed1990

Comparison of the classical immunofluorescent antibody tests for Epstein-Barr virus with commercially available test kits.

Twenty reference sera with previously reported titers plus 10 normal seropositive and 10 seronegative sera were used to determine which assay for the detection of antibodies to Epstein-Barr virus should be utilized in our laboratory. By three commercially available test systems and by slides prepared in our laboratory, all techniques detected the same number of samples positive for IgG antibodies to viral capsid antigen (VCA) and Epstein-Barr virus-determined nuclear antigen (EBNA), but the geometric mean titers (GMTs) varied. Major discrepancies arose in the sensitivity of detection of early antigen-diffuse (EA-D) and -diffuse and restricted (EA-DR). Slides prepared in our laboratory gave the best results, detecting 12 of 12 (100%). Slides prepared according to Gull and Hillcrest detected 11 of 12 (92%), and those prepared according to Zeus detected 9 of 12 (75%). From these data, we conclude that all of these methods for detection of VCA and EBNA are adequate. However, in determining antibody levels to EA-D and EA-DR, great care should be taken as to the source of the slide and specificity and sensitivity.

Antibodies, Viral↗

PubMed1990

Isolation of human herpesvirus-6 from clinical specimens using human fibroblast cultures.

The isolation and characterization of human herpesvirus-6 (HHV-6) has been hindered by the lack of cell lines useful for its rapid propagation. Recently, we have reported that the MRC-5 cell line (human diploid lung fibroblasts) was susceptible for HHV-6 infection. In this study, we report on the isolation of HHV-6 from the peripheral blood or buffy coat of three chronic fatigue syndrome patients, one post-liver transplant patient, and one severe chronic active Epstein-Barr virus syndrome patient using the MRC-5 cell line. Additionally, it was observed by Southern blot hybridization studies that four of five isolates had different restriction enzyme fragment patterns than the isolate obtained from the National Institutes of Health with Eco RI. These data suggest the usefulness of the MRC-5 cell line in the isolation and characterization of HHV-6 from various patients.

Adult↗

PubMed1990

Differential cellular susceptibility to Epstein-Barr virus infection in a patient with X-linked lymphoproliferative disease.

Epstein-Barr virus (EBV) is often associated with lethal lymphoproliferative diseases in immunologically compromised individuals. Recently, we have studied a 20-month-old boy with X-linked lymphoproliferative disease (XLP) who had succumbed to infectious mononucleosis (IM) complicated by fulminant hepatitis and virus-associated hemophagocytic syndrome following EBV infection. EBV genomes were detected in peripheral blood lymphocytes (PBL), cervical and mesenteric lymph nodes, liver, spleen, thymus, and bone marrow. According to restriction endonuclease analyses, the EBV-DNA pattern was similar in all samples except for the EBV-DNA from the bone marrow. Additionally, circular EBV-DNA (suggesting a latent infection) predominated in spontaneously established lymphoblastoid cell lines (LCLs) derived from both the lymph node and cord lymphocytes co-cultured with PBL. In contrast, both circular and linear EBV-DNA (suggesting a lytic infection) were noted in spontaneously established LCLs derived from his PBL. Furthermore, LCLs derived from both the lymph node and cord lymphocytes co-cultured with PBL expressed fewer reactive cells for early antigen (EA) and viral capsid antigen (VCA) than spontaneous LCLs from his PBL, thus providing evidence for different B cellular susceptibility to EBV infection in this patient with XLP. Finally, defective EBV-specific cytotoxic T cell activity was observed in this patient. Latent EBV infected cells may easily escape immunosurveillance by the host. These findings may explain the fatal course of EBV infection in this patient.

Antigens, Viral↗